Dr. Kudritzki (right) working with one of his collaborators, Dr. Fabio Bresolin.

Dr. Rolf-Peter Kudritzki, director of the UH Mānoa Institute for Astronomy (IfA), has received a Humboldt Research Award in recognition of his lifetime achievements in research. He will relinquish the IfA directorship at the end of 2010 and plans to use the award during a 2011 sabbatical in Germany to investigate the physics of galaxies.

During his sabbatical, Kudritzki will use the brightest stars in the universe as tools to dissect galaxies. He will analyze spectra of hundreds of supergiant stars (stars with radii as large as 300 times the sun and a hundred thousand times brighter) in distant galaxies. By applying completely new methods developed with his collaborators, which include UH Mānoa astronomers Drs. Fabio Bresolin and Miguel Urbaneja, Kudritzki will be able to use the spectra to determine the chemical compositions of galaxies and their distances from us. For instance, in spiral galaxies like our own Milky Way, the stars in the center have a higher percentage of elements heavier than hydrogen and helium than the stars at the edges of the rotating spiral arms.

Data about the chemical composition of galaxies can be used to test the present theory about how galaxies have formed in an expanding universe that is dominated by cold dark matter (matter that does not interact with any form of light and whose constituent particles move more slowly than light) and dark energy (the mysterious force that is accelerating the expansion of the universe). In fact, chemical composition is one of the very few ways to test this scenario quantitatively. So far, the present knowledge of the chemical composition of spiral galaxies is very uncertain. Kudritzki's new method will be the first to provide accurate numbers.

"This project is entirely new. Nobody has ever done anything like this, except Fabio, Miguel and me. Thus, I am truly excited and look forward to spending all my energy and time on it. I will use all the largest telescopes in the world for this project, including those on Mauna Kea and in Chile, and also the Hubble Space Telescope," said Kudritzki.

Humboldt Research Award winners are invited to spend a period of up to one year cooperating on a long-term research project with specialist colleagues at a research institution in Germany. Kudritzki will divide his time between Max Planck Institute for Astrophysics in Garching and University Observatory Munich.

UH Mānoa astronomers David Sanders and J. Patrick Henry are previous winners of Humboldt Research Awards.